<p>Outburst–rockburst composite dynamic disaster (ORCDD) is induced under the action of engineering disturbance. Many existing researches rely on small-scale physical experiments, which cannot accurately describe the disaster-causing process of composite dynamic disasters, resulting in a major bottleneck in the research of disaster prevention and control mechanisms. This study investigated the gas-bearing coal–rock composite structure. Through physical experiments, the impacts of gas pressure, coal intensity, and coal moisture content on ORCDD and its mode of action were explored, thus improving the comprehension of its disaster prevention mechanism. The findings indicate that raising the moisture content and intensity of coal will effectively inhibit the expansion and stripping of spallation, as well as weaken the length of failure front. Nevertheless, the spallation damage will be exacerbated by a rise in gas pressure, which will lead to the expansion of the failure front. The periodic spalling of spallation results in a serrated distribution for the coal–rock mixture mass influenced by the gas flow. Improved coal intensity can increase its anti-failure ability, inhibit the tensile stress caused by gas flow, and reduce the disaster intensity. However, when the specific coal intensity threshold is exceeded, the burst tendency of the coal–rock composite structure will be increased. The disaster intensity will be increased, the roof stress condition will be altered, and the disaster power will be enhanced by an elevation in gas pressure. If the gas pressure is beyond a specific threshold, it is more likely to induce outburst dominated by gas pressure. Elevating the coal moisture content will effectively decrease the severity and risk of ORCDD. Consequently, the original moisture content of coal can be adopted as an essential indicator to evaluate the risk of ORCDD. Combined with the development mechanism of coal spallation, the whole process of ORCDD is described, and the disaster prevention mechanism of different factors in each phase of disaster is clarified. In the prevention and control of ORCDD, it is suggested to take comprehensive prevention and control measures to improve coal intensity, coal seam water injection, and gas extraction simultaneously and to strengthen the control and monitoring of gas pressure threshold and coal rock strength difference threshold. This study verified the nonlinear strength characteristics and multi-factor coupling mechanism of ORCDD and provided a key parameter basis for the dynamic early warning of ORCDD.</p>